The next Zelda won't be too easy for veteran players, the longtime head of the series' development at Nintendo, Eiji Aonuma, recently told Kotaku. Plus, the new DS adventure will cater to Nintendo fan's research-proven taste for independent women.

In a brief e-mail interview with Kotaku in advance of the release of next month's The Legend of Zelda: Spirit Tracks, Aonuma explained that Link's latest adventure takes an unusual route to satisfying and challenging veteran gamers:

"One of our lead planners for the game is a programmer, so he has a different, more scientific or mathematical approach, so to say, to creating puzzles," he wrote to Kotaku. Aonuma is the producer on Spirit Tracks.

"Development team members, including [senior Nintendo developer] Mr. [Takashi] Tezuka and myself, actually got stuck in several places. So the dungeons and puzzles pose a different type of challenge than what we have utilized in previous games, and will certainly require longtime Zelda fans to approach each challenge differently. "

Getting more specific, he noted: "I believe that the latter half of the Tower of Spirits dungeon in The Legend of Zelda: Spirit Tracks — [which] players will revisit throughout the game — has puzzles which require a different type of approach from those of previous games,"

The chief architect of most of the major Zelda games, Aonuma has talked with your Kotaku deputy editor before about how to balance the creation of a new Zelda game to satisfy veteran fans and newcomers.

A couple of years ago, I suggested that his team consider giving the player their boomerang and bow-and-arrow from the get-go. that might be a way to make new Zeldas more alluring to veteran series gamers.

But never has he admitted to being stumped by some of the puzzles his designers have created.

The game won't all be harder.

Controls, for one thing, will be easier, Aonuma said.

I had asked him what his team had learned about the touch-screen controls implemented in the previous DS Zelda game, The Phantom Hourglass. That prompted this reply: "The one consistent piece of feedback we received about the controls in Phantom Hourglass was that it was too challenging to execute the roll move. You had to draw little circles at the edge of the screen to make Link roll. This is actually something we felt similarly about during development, but ended up not having enough time left in the schedule to implement another solution. In Spirit Tracks, this move is done by tapping anywhere on the screen, so hopefully players get more use out of it. "

Another tweak for the new game is in the Zelda character herself. In a change for the series, the Spirit Tracks Zelda takes on the game's adventure alongside Link, in the form of a spirit. She's not a damsel in distress just waiting to be saved. She's an active adventurer. Aonuma said she was designed out of a desire among both Zelda fans and developers to have a stronger princess.

"We recently received information from a survey conducted in the US that indicated that, among our female characters, users had a preference for those that were more on the independent side, such as Shiek and Tetra," he wrote. He was referring to the Zelda-in-disguise incarnations of Princess Zelda in The Legend of Zelda: The Ocarina of Time and The Legend of Zelda: The Wind Waker. "Making Zelda a more integral part of the game was also a goal for our Director, Mr. [Daiki] Iwamoto, so we set out with this element in mind when we started making the game."

Link's different in this new game too, of course. He so often is. Aonuma didn't divulge if or how Link will behave differently. Visually he looks like the Link in the GameCube's Wind Waker and the DS' Phantom Hourglass, but with the new game set 100 years after Hourglass, it's no surprise that this Link is at least a new hero.

"The Link character in Spirit Tracks is different from those featured in previous games," Aonuma said. "He's a brand new Link. The game does share ties with Phantom Hourglass and Wind Waker though. This is mostly communicated to the player through the Niko character, who appears in all three games. Of course he is much older in Spirit Tracks, and his aging conveys to the player that much time has passed across the timeline of all three games."